81307413 has 24 divisors (see below), whose sum is σ = 135660096. Its totient is φ = 46377600.

The previous prime is 81307409. The next prime is 81307417. The reversal of 81307413 is 31470318.

It is an interprime number because it is at equal distance from previous prime (81307409) and next prime (81307417).

It is not a de Polignac number, because 81307413 - 2² = 81307409 is a prime.

It is a super-2 number, since 2×81307413² = 13221790817505138, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81307417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22473 + ... + 25838.

It is an arithmetic number, because the mean of its divisors is an integer number (5652504).

Almost surely, 2^81307413 is an apocalyptic number.

It is an amenable number.

81307413 is a deficient number, since it is larger than the sum of its proper divisors (54352683).

81307413 is a wasteful number, since it uses less digits than its factorization.

81307413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48345 (or 48342 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 81307413 is about 9017.0623265008. The cubic root of 81307413 is about 433.2215458522.

The spelling of 81307413 in words is "eighty-one million, three hundred seven thousand, four hundred thirteen".